The invention resides in a crankcase with a crankshaft chamber in which a crankshaft is arranged, including a front end bearing cover with a bearing top part and a bearing bottom part for supporting the crankshaft and a front gear drive for driving an auxiliary unit comprising a first drive gear disposed on the crankshaft, a second drive gear disposed on the auxiliary unit and an intermediate gear in meshing engagement with the first and the second drive gears.
In an internal combustion engine, the drive for the auxiliary units such as the oil and water pumps is arranged at the end of the engine opposite the power output shaft end. The drive is in the form of front end spur gears including a first drive gear disposed on the camshaft, a second drive gear disposed on the auxiliary unit and an intermediate transmission gear. In the area of the support structure for the intermediate transmission gear there is the crankshaft chamber which does not offer a mounting possibility for a support structure the intermediate gear since the crankcase wall has an insufficient wall thickness. This problem is solved by supporting the intermediate transmission gear between a first and a second support plate which form a bearing unit. Such a solution is known from DE 199 60 130 A1. This support unit abuts the front side of the crank housing and is bolted to the upper bearing part (upper bearing bridge). However, because of the complex arrangement, the support unit is sensitive to vibrations so that a hydraulic play compensation element is required for damping the vibrations.
A more simple arrangement is disclosed in DE 100 02 538 A1. Herein, the intermediate transmission gear is arranged via a support pin on an elongated support plate. The support plate is mounted to the crankcase by way of two connecting areas so that, after assembly, the intermediate transmission gear is disposed between the housing wall and the support plate. The connecting areas are again disposed on the axis of symmetry of the intermediate transmission gear which extends normal to the axis of rotation. By an arrangement for applying a pretensioning force to the support plate, the drive gears and the intermediate gear are kept in proper engagement. However, because of the type of design this solution cannot be used in proximity of the crankcase chamber. Since the support plate is subjected to bending by the changing load of the drive gears and the intermediate transmission gear, the support plate must be of solid construction.
It is the object of the present invention to provide a simple gear drive arranged in front of a crankcase of an internal combustion engine for driving auxiliary components of the internal combustion engine.